1. Field of Invention
The present invention relates to a pump with a detachable pressure gauge.
2. Related Prior Art
Cycling is a very popular activity for traveling and/or exercising. Many riders like to carry pumps with them for use in case of emergency. Some of the pumps for bicycles are equipped with pressure gauges. These conventional pressure gauges are secured to the pumps, i.e., they cannot be detached from the pumps. Compared with the pumps, the conventional pressure gauges are bulky and cause inconvenience in operation of the pumps. Therefore, riders using pumps equipped with pressure gauges often wish that they had pumps without pressure gauges. Many riders simply choose not to have pumps equipped with pressure gauges although they know that sometimes pressure gauges are needed for precise pumping.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
It is the primary objective of the present invention to provide a pump with a detachable pressure gauge.
According to the present invention, a pump includes a cylinder, a piston, a rod, a handle, a nozzle and a pressure gauge. The piston is received in a space extending through the cylinder. To pump, the piston is reciprocated in the cylinder. The rod is connected with the piston so that the piston is moved via operating the rod. The handle is connected with the rod for facilitating the operation of the rod. The nozzle is in communication with the cylinder. A pressure gauge can be engaged with and disengaged from the nozzle.
A flow control unit is in communication with the nozzle for detachable engagement with the pressure gauge. The flow control unit provides an open position when engaged with the pressure gauge and a closed position when disengaged from the pressure gauge.
The flow control unit includes a housing, a body, a spring and a cap. The housing is received in a space defined in the nozzle. The housing through which a channel extends includes an annular ridge formed on an internal face thereof. The body is received and can be moved in the channel. The body includes an annular flange formed thereon for abutment against a side of the annular edge. The spring is mounted on the body, and the cap is mounted on the body so that the spring is compressed between the cap and an opposite side of the annular edge. Thus, the spring tends to drive the annular flange into abutment against the annular edge.
The flow control unit includes an annular seal mounted on the body so as to improve sealing between the annular flange and the annular edge.
The pressure gauge includes a tube for disengaging the annular flange from the annular edge by pressing the cap. The tube defines a channel for communication with the channel defined in the housing, thus flowing air from the nozzle to the pressure gauge.
The pump includes a retaining device for retaining the tube in engagement with the flow control unit.
In a first aspect, the retaining device includes an annular rim formed on the nozzle and a ring mounted on the tube for engagement with the annular rim.
The pressure gauge may include an annular seal mounted on the tube so as to improve sealing between the tube and the annular rim.
In a second aspect, the annular rim includes two flanges formed on an external face, and the ring includes two hooks formed on an internal face for engagement with the flanges of the annular rim.
In a third aspect, the retaining device includes a ring mounted on the housing for engagement with the tube.
The pressure gauge includes an annular seal attached to an end of one of the housing and the tube.
Other objectives and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the attached drawings.